Environmental evaluation of concrete made from recycled concrete aggregate implementing life cycle assessment

• The paper evaluates the environmental impact of natural and recycled aggregate concretes based on LCA.
• Results were obtained according to both NF P 01–010 and EN 15804 standards.
• The environmental behavior of concrete established from waste materials remains acceptable.
• The use of recycled materials allows reducing either conversion or occupation of land.

Recycled concrete aggregates from demolition constitute one of the largest waste streams within the developed countries. These study aims to quantify environmental impacts associated with mixing compositions of concrete made of waste materials by using LCA. Environmental performances of natural, recycled and mixed 20-mm concrete samples, formulated with the same mechanical strength regarding the functional unit, were evaluated. Eight millimeter concrete samples, formulated with natural or recycled (concrete or terracotta brick) aggregates – with the same volume composition of the granular skeleton for apparent concrete application regarding the functional unit – were also studied. The LCA results are presented using various impact assessment methods, according to both EN 15804 and NF P 01–010 standards. Recycled samples present good environmental behavior, even if recycled materials (sand and aggregates) involve different operations (crushing against extraction, etc.). The terracotta 8-mm concrete sample presents low environmental impacts in comparison with the other 8-mm concrete samples. This sample exhibits a low aggregate density, which decreases transport impacts, and good mechanical strengths, which improves its lifetime.